package demo;

class MyValue {
    private int val;

    public int getVal() {
        return val;
    }

    public void setVal(int val) {
        this.val = val;
    }
}

public class Test {
    public static void swap(MyValue myV1, MyValue myV2) {
        int tmp = myV1.getVal();
        //myV1.val = myV2.val;
        myV1.setVal(myV2.getVal());
        //myV2.val = tmp;
        myV2.setVal(tmp);
    }

    public static void main(String[] args) {
        MyValue myValue1 = new MyValue();
        myValue1.setVal(10);

        MyValue myValue2 = new MyValue();
        myValue2.setVal(20);
        swap(myValue1,myValue2);

        System.out.println(myValue1.getVal());
        System.out.println(myValue2.getVal());

    }
}
